Article of footwear with multiple layers, retention system for an article of footwear, and methods of manufacture

ABSTRACT

One aspect of the present disclosure provides a knitted component forming an overfoot portion and an underfoot portion of an article of footwear. The knitted component may include a first layer defining a void and a second layer second layer at least partially surrounding the first layer. The second layer may form an outer surface on the overfoot portion and the underfoot portion, and a portion of the first layer may be continuous with a portion of the second layer in an ankle region of the knitted component. An interstitial space may be formed between the first layer and the second layer, and a component may be disposed between the first layer and the second layer.

RELATED APPLICATIONS

This application claims the benefit of priority of U.S. ProvisionalApplication No. 62/491,898, filed Apr. 28, 2017, which is hereinincorporated by reference in its entirety. This application also claimsthe benefit of priority of U.S. Provisional Application No. 62/365,114,filed Jul. 21, 2016, which is herein incorporated by reference in itsentirety.

BACKGROUND

Conventional articles of footwear generally include two primaryelements: an upper and a sole structure. The upper is secured to thesole structure and forms a void within the article of footwear forcomfortably and securely receiving a foot. The sole structure is securedto a lower surface of the upper so as to be positioned between the upperand the ground. In some articles of footwear, the sole structure mayinclude a midsole and an outsole. The midsole may be formed from apolymer foam material that attenuates ground reaction forces to lessenstresses upon the foot and leg during walking, running, and otherambulatory activities. The outsole may be secured to a lower surface ofthe midsole and forms a ground-engaging portion of the sole structurethat is formed from a durable and wear-resistant material.

The upper of the article of footwear generally extends over the instepand toe areas of the foot, along the medial and lateral sides of thefoot, and around the heel area of the foot. An ankle opening in a heelarea generally provides access to the void in the interior of the upper.A lacing system is often incorporated into the upper to adjust the fitof the upper, thereby facilitating entry and removal of the foot fromthe void within the upper. The upper may include a tongue that extendsunder the lacing system to enhance adjustability of the footwear, andthe upper may incorporate a heel counter to limit movement of the heel.

SUMMARY

One aspect of the present disclosure provides a knitted componentforming an overfoot portion and an underfoot portion of an article offootwear. The knitted component may include a first layer defining avoid and a second layer second layer at least partially surrounding thefirst layer. The second layer may form an outer surface on the overfootportion and the underfoot portion, and a portion of the first layer maybe continuous with a portion of the second layer in an ankle region ofthe knitted component. An interstitial space may be formed between thefirst layer and the second layer, and a component may be disposedbetween the first layer and the second layer.

In some embodiments, the first layer and the second layer may be formedon a circular knitting machine, and the second layer may be invertedwith respect to the first layer. A seam may be formed at least in thesecond layer in a toe region of the knitted component. The seam may jointhe first layer to the second layer. A tension force of the second layermay retain the component in an underfoot area of the interstitial space.The interstitial space may be substantially free of adhesive. Thecomponent may be a midsole. The knitted component may further include aretention system formed in the second layer, the retention system havinga plurality of first yarns and a plurality of second yarns, where thefirst yarns and the second yarns at least partially form the secondlayer of the knitted component, where the second yarns bias theretention system to a first state, and where the retention system exertsa tension force in a second state.

In another aspect, the present disclosure provides an upper with a firstlayer and a second layer, where the second layer at least partiallysurrounds the first layer, where a portion of the first layer iscontinuous with a portion of the second layer, and where the first layeris continuous with the second layer in at least a portion of an ankleregion of the upper. A component may be disposed between the first layerand the second layer, where the component includes a material havingdifferent properties than the first layer and the second layer.

In some embodiments, the component may have a rigidity greater than thefirst layer and the second layer. The component may have a shape of abootie that is coextensive with at least a forefoot region and a midfootregion of the upper. The bootie may be coextensive with a portion of aheel region. The component may have a greater stretch resistance thanthe first layer and the second layer. The first layer and the secondlayer may be formed by a knitted component. A pocket may be disposedbetween the first layer and the second layer, where the pocket receivesthe component. A seam that joins the first layer to the second layer ina toe region of the upper may be included.

In another aspect, the present disclosure includes a method of making anarticle of footwear. The method may include pulling an open toe regionof an element towards a main fold line disposed between a first portionof the element and a second portion of the element so that an interiorsurface of the first portion of the element is exposed during thepulling operation, pulling the open toe region past the main fold lineand onto the second portion so that the first portion substantiallysurrounds the second portion and a fold is formed in an ankle region ofthe article of footwear, aligning the open toe region of the elementwith a closed toe region of the second portion of the element, andforming a seam to join the open toe region with the closed toe region.

In some embodiments, the element may be a knitted component, and themethod may further include forming the knitted component on a knittingmachine. An interstitial space may be formed between the first portionand the second portion. The method may further include inserting acomponent between the first portion and the second portion in theinterstitial space.

BRIEF DESCRIPTION OF THE DRAWINGS

The embodiments of the present disclosure can be better understood withreference to the following drawings and description. The components inthe figures are not necessarily to scale, emphasis instead being placedupon illustrating the certain principles. Moreover, in the figures, likereferenced numerals designate corresponding parts throughout thedifferent views.

FIG. 1 is a perspective side view of an embodiment of an article offootwear having a multilayer upper with a component disposed between thelayers of the upper.

FIG. 2 is an exploded view of the embodiment of an article of footwearof FIG. 1.

FIG. 3 is a cross-sectional view of a forefoot region of the embodimentof the article of footwear of FIG. 1, where the cross-section is takenalong line 3-3.

FIG. 4A is a cross-sectional view of a heel region of the embodiment ofthe article of footwear of FIG. 1, where the cross-section is takenalong line 4-4.

FIG. 4B is a cross-sectional view of a heel region of another embodimentof an article of footwear.

FIG. 5 is an embodiment of an unfolded knit element that may be used toform a multilayer knit upper.

FIG. 6 depicts an embodiment of a first step in forming a multilayerknit upper from the unfolded knit element shown in FIG. 5.

FIG. 7A depicts an embodiment of a second step in forming a multilayerknit upper from the unfolded knit element shown in FIG. 5.

FIG. 7B depicts an embodiment of a third step in forming a multilayerknit upper from the unfolded knit element shown in FIG. 5.

FIG. 8 depicts an embodiment of a completed multilayer knit upper formedfrom the unfolded knit element shown in FIG. 5.

FIG. 9 depicts a perspective side view of an embodiment of an article offootwear having a multilayer upper with various zonal pockets andinserts.

FIG. 10 is a cross-sectional view of a forefoot region of the embodimentof the article of footwear shown in FIG. 9, where the cross-section istaken along line 10-10.

FIG. 11 is a partial sectional view of an embodiment of an upper of thearticle of footwear shown in FIG. 9 showing an exterior surface of aninner layer of the upper.

FIG. 12 depicts an embodiment of a zonal pocket.

FIG. 13 is a cross-sectional view of an embodiment of a zonal pocket,where the cross-section is taken along line 13-13 of FIG. 12.

FIG. 14 is a perspective side view of another embodiment of an articleof footwear having a multilayer upper with various zonal pockets andinserts.

FIG. 15 is a partially exploded view of the article of footwear of FIG.14, showing various zonal inserts.

FIG. 16 is an embodiment of an upper for an article of footwear, wherethe upper includes various zones having visibly different colors andvisible bite lines.

FIG. 17 is an embodiment of a knit element with knit-in zones and bitelines, where the knit element may be used to form a multilayer upperwith visible bite lines.

FIG. 18 illustrates a step of affixing an embodiment of an upper with avisible bite line with an embodiment of a sole structure.

FIG. 19 is an embodiment of an article of footwear with a visible biteline with an embodiment of a sole structure attached to the upperproximate the visible bite line.

FIG. 20A is an embodiment of an article of footwear with a retentionsystem in a first state.

FIG. 20B is the embodiment of an article of footwear shown in FIG. 20A,where the retention system is shown in a second state.

DETAILED DESCRIPTION

Referring to FIG. 1, a first embodiment of an article, such as anarticle of footwear 100 is shown. Article of footwear 100 includes anembodiment of an upper 101 with a component sandwiched between twolayers and an optional sole structure 103. Article of footwear 100 isdisclosed as having a general configuration suitable for walking orrunning. Concepts associated with the footwear, including upper 101, mayalso be applied to a variety of other athletic footwear types, includingbut not limited to baseball shoes, basketball shoes, cross-trainingshoes, cycling shoes, football shoes, soccer shoes, sprinting shoes,tennis shoes, and hiking boots. The concepts may also be applied tofootwear types that are generally considered to be non-athletic,including dress shoes, loafers, sandals, and work boots. The conceptsdisclosed herein apply, therefore, to a wide variety of footwear types.Furthermore, the concepts disclosed herein may apply to articles beyondfootwear, such as accessories or apparel.

In the embodiment of FIG. 1, upper 101 generally provides a comfortableand secure covering for the foot. The upper 101 may include an overfootarea 160 and an optional underfoot area 162 surrounding a void 119. Assuch, the foot of a wearer may be located within a void 119 toeffectively secure the foot within article of footwear 100 or otherwiseunite the foot and article of footwear 100. Moreover, sole structure 103may be secured to a lower area (e.g., the underfoot area 162) of upper101 or may partially or completely reside within a portion of the upper101 such as an interstitial space as described below, and may bepositioned between the foot and the ground to attenuate ground reactionforces (e.g., cushion the foot), provide traction, enhance stability,and/or influence the motions of the foot.

For reference purposes, article of footwear 100 upper 101 may be dividedgenerally along a longitudinal axis (heel-to-toe) into three generalregions: a forefoot region 109, a midfoot region 110, and a heel region111. Forefoot region 109 generally includes portions of article offootwear 100 corresponding with the toes and the joints connecting themetatarsals with the phalanges. Midfoot region 110 generally includesportions of article of footwear 100 corresponding with an arch area ofthe foot. Heel region 111 generally corresponds with rear portions ofthe foot, including the calcaneus bone. Article of footwear 100 alsoincludes a lateral side 107 and a medial side 105, which extend througheach of forefoot region 109, midfoot region 110, and heel region 111 andcorrespond with opposite sides of article of footwear 100. Moreparticularly, lateral side 107 corresponds with an outside area of thefoot (i.e., the surface that faces away from the other foot), and medialside 105 corresponds with an inside area of the foot (i.e., the surfacethat faces toward the other foot). Forefoot region 109, midfoot region110, heel region 111, lateral side 107, and medial side 105 are notintended to demarcate precise areas of article of footwear 100. Rather,forefoot region 109, midfoot region 110, heel region 111, lateral side107, and medial side 105 are intended to represent general areas ofarticle of footwear 100 to aid in the following discussion.

In some embodiments, sole structure 103 may generally include a midsole106 and/or an outsole 108. A midsole 106 may be secured to a lowersurface of upper 101, or may be positioned within an interstitial space129 between an outer knit layer 120 and an inner knit layer 122, asdescribed below. When midsole 106 occupies the interstitial space 129,tension in the outer knit layer 120 may retain midsole 106 in anunderfoot position between the inner knit layer 122 and outer knit layer120. The midsole 106 may reside within the interstitial space 129 withor without additional elements to retain the midsole 106 in theunderfoot area, for example adhesives, stitches, heat bonding, RFwelding, or sonic welding. The absence of adhesives retaining midsole106 within the interstitial space 129 may advantageously contribute tomore compliant and reactive on-foot feel. However, outsole 108 may beadditionally or alternatively be secured to the lower surface of upper101 with the use of an adhesive or other suitable mechanical or chemicalmechanisms or means. Midsole 106 may be formed from a compressiblepolymer foam element (e.g., a polyurethane or ethylvinylacetate foam)that attenuates ground reaction forces (e.g., provides cushioning) whencompressed between the foot and the ground during walking, running, orother ambulatory activities. Additionally or alternatively, midsole 106may incorporate plates, moderators, fluid-filled chambers, lastingelements, and/or motion control members that further attenuate forces,enhance stability, or influence the motions of the foot.

An outsole 108 having a ground-engaging surface can be disposed at alower surface of midsole 106 or a lower surface of upper 101 in someembodiments. The outsole 108 may be at least partially formed with atextured wear-resistant rubber material, thus providing a tread element112 to impart traction.

Although the depicted configuration of sole structure 103 provides anexample of a sole structure that may be used in connection with upper101, a variety of other configurations for sole structure 103 mayalternatively be used. In some embodiments, for example, an externalsole structure 103 may be omitted, and portions of upper 101 may betreated or otherwise configured to provide a suitable ground-engagingsurface.

As depicted, upper 101 includes a first or outer knit layer 120 and asecond or inner knit layer 122. In some embodiments, outer knit layer120 substantially surrounds inner knit layer 122, and outer knit layer120 may form an exterior surface 121 (shown in FIGS. 4A-4B) of upper101. In some embodiments, such as shown in FIG. 1, outer knit layer 120entirely covers inner knit layer 122 so that inner knit layer 122 is notvisible from an exterior perspective after assembly. In otherembodiment, outer knit layer 120 covers only a portion of inner knitlayer 122 so that another portion of inner knit layer 122 is visibleafter assembly from the exterior perspective.

Outer knit layer 120 and inner knit layer 122 are arranged or otherwiseconfigured in some embodiments to create an interstitial space 129(e.g., a gap) between outer knit layer 120 and inner knit layer 122. Oneor more component(s) 124 may be positioned in interstitial space 129between outer layer 120 and inner layer 122. Component 124 may be abootie, midsole, cleat plate, a water-resistant membrane, or any othersuitable device. Thus as shown in FIG. 1, a three-layer upper may beprovided with an outer knit layer 120, an inner knit layer 122, and thecomponent 124 positioned between outer knit layer 120 and inner knitlayer 122.

In some embodiments, the component 124 disposed in interstitial space129 may be structured or otherwise configured to provide a specificshape to upper 101 such that the upper 101 is able to hold a specificshape when a foot is not disposed within upper 101 (e.g., when the otherlayers of upper 101 lack the structural characteristics to hold adesirable three-dimensional shape on their own). For example, in someembodiments, such as the embodiment shown in FIG. 1, the component 124may advantageously facilitate the article of footwear retaining a shapetypical of athletic footwear with or without receipt of a foot withinthe void.

In some embodiments, such as the embodiment shown in FIGS. 1-4A, thecomponent 124 is a bootie. Component 124, as shown best in FIG. 2, mayhave the general configuration of an athletic upper. Component 124 maybe configured (e.g., sized and shaped) to receive and/or substantiallycover a foot of a user when the foot is inserted into upper 101.Component 124 may be made of a material that has sufficient rigidityand/or stiffness to maintain its established three-dimensional shape,and may include a material that is more rigid or stiff than the outerknit layer 120 and the inner knit layer 122. In some embodiments,component 124 may be a single layer of material. Additionally oralternatively, component 124 may be made from a nonwoven textile (and itis noted that a knitted textile is distinct from a nonwoven textile). Insome embodiments, component 124 may include thermoplastic or thermosetportions so that component 124 may be heat set to hold a specific shape.

In some embodiments, such as the embodiment shown in FIG. 4B, component124 is a midsole 106 positioned within interstitial space 129. Tensionin outer layer 120 may retain midsole 106 in an underfoot positionbetween inner layer 122 and outer layer 120, for example. Midsole 106may reside within interstitial space 129 with or without additionalelements to retain midsole 106 in the underfoot area, for exampleadhesives or stitches. In embodiments where the midsole 106 resideswithin the interstitial space 129 without additional elements securingit to the outer or inner knit layers 120, 122, the midsole 106 maybetter conform to a wearer's foot during ambulatory activities due tothe elimination of at least one flexibility-reducing adhesive layer.Additionally, the elimination of adhesive may advantageously reduce theneed for certain materials and/or manufacturing steps, which mayincrease manufacturing efficiency and lower the overall cost of thearticle of footwear. As described above, midsole 106 may be formed fromone or more materials that provide cushioning when compressed betweenthe foot and the ground during walking, running, or other ambulatoryactivities. Midsole 106 may also (or alternatively) incorporate otherelements that further attenuate forces, enhance stability, or influencethe motions of the foot.

Component 124 may be made of multiple layers of material. Optionally,component 124 may include provisions for cushioning, such as relativelythick portions, inflatable portions, foam portions, or the like.Additionally or alternatively, component 124 may include provisions forprotection, such as thicker portions, rigid portions such as plates,stiffened portions, or the like. In some embodiments, component 124 mayhave apertures or may otherwise include discontinuities so thatcomponent 124 essentially provides a scaffold that establishes thethree-dimensional shape while retaining breathability and flexibility.

As shown in FIG. 3, component 124 may establish the shape of an interiorvoid 119, which is the opening within upper 101 into which a foot of auser is inserted for use. An interior surface 123 of inner knit layer122 may define and form a surface of interior void 119. When inner knitlayer 122 is formed of a relatively flexible knit, inner knit layer 122may have difficulty in maintaining a specific, three-dimensional shapesuch as the shape shown in FIG. 3. Thus, component 124 may communicatewith the inner knit layer 122 to established and retain a suitable shapeof interior void 119.

Component 124 may be coextensive with outer knit layer 120 and/or innerknit layer 122 at least at some locations and not at others. Referringto FIG. 4A, which shows a cross-section of upper 101 taken along line4-4 in heel region 111, component 124 is coextensive with outer knitlayer 120 and inner knit layer 122 at a bottom portion of article offootwear 100. Upper or top edges of component 124 terminate within ankleregion 102 of upper 101 while outer knit layer 120 and inner knit layer122 extend beyond the component 124 to form ankle region 102.Specifically, component 124 extends from a lateral bootie top edge 131on lateral side 107 to a medial bootie top edge 130 on medial side 105.Outer knit layer 120 and inner knit layer 122 extend beyond lateralbootie top edge 131 and medial bootie top edge 130 to form ankle region102 and join at medial fold 126 and lateral fold 128. As shown in FIG.4A, in ankle region 102, medial interstitial space 125 and lateralinterstitial space 127 are empty, allowing ankle region 102 to behaveand/or have characteristics more like a traditional sock. For example,ankle region 102 may have the flexibility to conform to the ankle of awearer during use and/or to have suitable stretchability to accommodatethe insertion and removal of the foot of a wearer.

In some embodiments, outer knit layer 120 and inner knit layer 122 aremade from a common knit element 118 that is folded to form the layers120 and 122. In the embodiment shown in FIG. 1, knit element 118 hasbeen doubled over to form two layers. One embodiment of such an unfoldedknit element 138 is shown in FIG. 5. Making both layers of knit element118 of upper 101 from a common unfolded knit element 138 may reducecosts, both in terms of knitting time and waste reduction, but alsobecause folding unfolded element 138 into the folded orientation of knitelement 118 may take less time and labor than aligning two separatepieces of material and joining the separate pieces of material together.

FIGS. 5-8 show an embodiment of turning unfolded element 138 into adouble-layer knit element like knit element 118. FIG. 5 shows anembodiment of unfolded element 138, where unfolded element 138 has agenerally tubular, sock-like configuration. Unfolded element 138includes two portions: a first portion 141 and a second portion 143.First portion 141 and second portion 143 may be nearly identical inshape, though mirror-images and/or oppositely-oriented generallysymmetrical portions. In some embodiments, first portion 141 and secondportion 143 may have a foot-like shape with a toe such as first toe 140and second toe 142, and a shaped heel such as first heel 145 and secondheel 146.

In the illustrated embodiment of FIG. 5, first portion 141 includes afirst or open toe 140 so that a portion of an interior surface 144 ofunfolded element 138 is visible. In contrast, the second portion 143 mayhave a second or closed toe 142, that is closed either by joining edgestogether during a post-knitting process, during knitting (e.g., edgesjoined by a knit structure of the knit element 118 formed on a knittingmachine), or otherwise closed by desirable or accepted methods. Closedtoe 142 may alternatively be left open, at least initially, for example,in a manner like open toe 140. In such embodiments, closed toe 142 mayultimately be closed to form a seam as discussed below in forming a seamto join open toe 140 to inner knit layer 122.

Unfolded element 138 may be made using a suitable knitting process. Insome embodiments, unfolded element 138 may be manufactured on a circularknitting machine. In some embodiments, first portion 141 and secondportion 143 are made from the same type of yarn and with the same typeof knit stitches. In other embodiments, first portion 141 and secondportion 143 may be made from different types of yarn, different knitstitches and/or other knit structures, and/or with different knit stitchdensities. Similarly, within each portion, first portion 141 and secondportion 143 may be made with the same type of yarn and with the sametype of knit stitches or other knit structures. In other embodiments,within first portion 141, first portion 141 may include different typesof yarn, different knit stitches or other knit structures, and/ordifferent knit stitch densities. Similarly, second portion 143 mayinclude different types of yarn, different knit stitches or other knitstructures, and/or different knit stitch densities within second portion143.

First portion 141 and second portion 143 may be considered to be dividedby a main fold line 135. Main fold line 135 may be an imaginary linethat apportions unfolded element 138 into first portion 141 and secondportion 143. In some embodiments, main fold line 135 may divide unfoldedelement 138 approximately in half. In other embodiments, first portion141 may be slightly larger than second portion 143, which may beadvantageous when first portion 141 will be folded over second portion143, although it is also contemplated that second portion 143 may belarger. First portion 141 may, in some embodiments, surround orsubstantially surround second portion 143 to form outer knit layer 120.Thus, when first portion 141 is not substantially larger than secondportion 143, first portion 141 may have sufficient stretch to encompasssecond portion 143 and to allow for interstitial space 129. In theseembodiments, the tension in the yarns of first portion 141 may assist inholding any components positioned in interstitial space 129 in a desiredposition.

As shown in FIG. 6, a step in forming knit element 118 from unfoldedelement 138 includes grasping open toe 140 and turning the open end offirst portion 141 essentially inside-out so that interior surface 144becomes an exterior surface and first intermediate fold 150 is formed infirst portion 141. In some embodiments, in the final product, interiorsurface 144 of unfolded element 138 becomes exterior surface 121 (shownin FIG. 3). After first portion 141 is turned or flipped inside-out,open toe end 140 is pulled in first fold direction 151. First folddirection 151 is in the direction towards main fold line 135.

FIG. 7A shows a subsequent point in the folding process. As shown, opentoe 140 has been pulled past first portion heel 145 as shown in FIG. 6so that first portion heel 145 is also turned inside out. Open toe 140is also depicted as pulled past second portion heel 146 in a second folddirection 153. Open toe 140 is shown as approaching closed toe 142. Atthis stage, interior surface 144 may form a majority of an exteriorsurface of the illustrated element. The wearable orientation of outerknit layer 120 and inner knit layer 122 is, at this point, more clearlyvisible.

FIG. 7B shows yet another optional point in the folding process, whereinopen toe 140 is pulled past closed toe 142 prior to the final step. Bypulling open toe 140 past closed toe 142, technical properties and/oraesthetic qualities of outer knit layer 120 may extend up to and becoterminous with closed toe 142. Furthermore, at this stage, pullingopen toe 140 past closed toe 142 may enable forming a toe seam 132 byalternative post-process methods, described below.

FIG. 8 shows an embodiment of a final step in the folding process. Inthis step, open toe 140 may be pulled proximate closed toe 142. In someembodiments, such as the illustrated embodiment, open toe 140 alignswith closed toe 142. In other embodiments, open toe 140 may fall shortof closed toe 142 or be pulled past closed toe 142 (as shown in FIG.7B). In embodiments where open toe 140 may be pulled past closed toe142, outer knit layer 120 may be temporarily joined with closed toe 142prior to forming the toe seam 132. Also, an excess portion 141 of outerknit layer 120 that extends beyond closed toe 142 may be removed priorto or subsequent to forming the toe seam 132. Open toe 140 may beaffixed to inner knit layer 122 to form the toe seam 132, which may bepositioned in an over-toe area, and underfoot area, or other area. Toeseam 132 may be formed by one or more steps, including but not limitedto stitching, adhesive bonding, heat bonding if the yarns of outer knitlayer 120 and inner knit layer 122 include thermoset or thermoplasticproperties, welding through an RF welding or sonic welding process, orthe like. Heat bonding, RF welding, and sonic welding may providebenefits over other types of joining process by reducing labor costs andmaterial waste, by enabling toe seam 132 to have smaller dimensionsand/or reside below a bite line where it is not visible (for example inan underfoot area), and/or by providing a seamless on-foot feel to theuser (for example, by eliminating “ears” created on the medial andlateral portions of the toe area by traditional toe-closing steps suchas stitching). Any of the foregoing methods to form toe seam 132 may becarried out as a post-process step, i.e., after the upper is removedfrom a knitting machine.

When outer layer 120 and inner layer 122 are in their wearableconfiguration, as shown in FIG. 8, knit element 118 may extend from toeseam 132 to main fold line 135. Proximate main fold line 135 is a footinsertion opening 104. Also proximate main fold line 135 is a main fold.As shown in FIGS. 4A-B, main fold is shown at a top of ankle region 102and includes a medial fold 126 and a lateral fold 128. The main fold maybe continuous around foot insertion opening 104. Medial fold 126 andlateral fold 128 may be formed when first portion 141 fully overlapssecond portion 143. Main fold at main fold line 135 (shown in FIG. 8)may be a bend in knit element 118 that preserves the nature (e.g. thecontinuity) of unfolded knit element 138 while forming two distinctlayers: outer knit layer 120 and inner knit layer 122.

In some embodiments, component 124 may be positioned on first portion141 and/or second portion 143 or between these portions 141 and 143prior to or during the folding of unfolded element 138 into knit element118. In one particular example (e.g., when the component 124 is a bootieas depicted), second portion 143 may be inserted into component 124 thenfirst portion 141 may be folded around component 124. In otherembodiments, component 124 (and/or other components) may be insertedbetween first portion 141 and second portion 143 after portions 141 and143 are substantially folded or otherwise manipulated into theirwearable orientation.

FIGS. 9-19 show various embodiments of an article of footwear with aknitted element, where different components and/or knit structures areused in different zones of an article of footwear to achieve differentproperties in different zones. For example, different portions or zonesof an article of footwear may benefit from different structural orperformance properties. In some zones, such as in the forefoot region,breathability and flexibility are beneficial. In other zones, such as ina heel or toe, rigid support and protection may be beneficial.

In the embodiment(s) shown in FIGS. 9-13, an article of footwear 200includes an upper 201 and an optional sole structure 203. In mostrespects, upper 201 is similar to upper 101 and second sole structure203 is similar to sole structure 103, both of which are discussed abovewith reference to FIGS. 1-8. For example, second knit element 218 mayoptionally be made from the same materials and folded in the same way asknit element 118 discussed above. In some embodiments, such as theembodiment shown in FIGS. 9-13, second knit element 218 may include atleast one zonal pocket which is configured to contain at least one zonalinsert.

Upper 201 may include zonal pockets sandwiched between a first knitlayer 220 and a second knit layer 222. Zonal pockets and inserts may beprovided to produce different responses and properties in differentparts of article of footwear 200. In the embodiment shown in FIG. 9,three zonal pockets are provided: a first zonal pocket 230 disposed insecond heel region 211, a second zonal pocket 232 disposed on a medialside 205 of second midfoot region 210, and a third zonal pocket 234disposed in a toe region of second forefoot region 209. As shown best inFIG. 11, first zonal pocket 230 is configured to receive a first zonalinsert 231 within a first pocket interior 236, second zonal pocket 232is configured to receive a second zonal insert 233 within a secondpocket interior 238, and third zonal pocket 234 is configured to receivea third zonal insert 235 within a third pocket interior 240.

Greater or fewer zonal pockets may be provided in other embodiments. Insome embodiments, the number of zonal pockets may exceed the number ofzonal inserts. For example, when a single design of knit element 218 isprovided for a number of different configurations, some of the pocketsmay remain empty in some configurations. In other embodiments, thenumber of zonal pockets may be less than the number of zonal inserts,such as when zonal inserts may be provided in a kit forinterchangeability or when more than one zonal insert is intended to bepositioned in a zonal pocket for a finer degree of control over theproperties contributed by the zonal inserts.

As shown in the cross-sectional view of FIG. 10, which is taken alongline 10-10 of FIG. 9 and through second zonal pocket 232, second zonalpocket 232 is disposed in an interstitial space 225 formed between outerknit layer 220 and inner knit layer 222 on medial side 205 of upper 201.Though second zonal pocket 232 is discussed, the same principles ofplacement, construction, and performance may apply equally to any zonalpocket discussed with respect to this or any other embodiment.

As illustrated in FIG. 10, a second pocket panel 239 extends betweenoutward-facing surface 224 and inward-facing surface 226 withininterstitial space 225. In some embodiments, second pocket panel 239 maybe attached to outward-facing surface 224, while in other embodiments,pocket panel 239 may be attached to inward-facing surface 226. In someembodiments, second pocket panel 239 may be formed integrally (e.g.,formed with a common knit structure on a knitting machine) with at leastone of second outer knit layer 220 and/or second inner knit layer 222.In other embodiments, second pocket panel 239 may be formed separatelyand then sewed, adhered, heat bonded, and/or welded to at least one ofouter knit layer 220 and inner knit layer 222.

Second pocket panel 239 may define a second pocket interior 238. In theillustrated embodiment, second pocket interior 238 is defined by secondpocket panel 239 and outward-facing surface 224. In other embodiments,second pocket interior 238 may be defined by second pocket panel 239 andinward-facing surface 226. Thus, one of outer knit layer 220 and innerknit layer 222 may form one wall of a pocket while the other wall of thepocket may be formed from second pocket panel 239. In some embodiments,another pocket panel may be included to define another wall of secondpocket interior 238.

Second pocket interior 238 may configured to receive second zonal insert233. In the illustrated embodiment, second zonal insert 233 ispositioned between second pocket panel 239 and outward-facing surface224. In other embodiments, second zonal insert 233 may be positionedbetween second pocket panel 239 and inward-facing surface 226. In otherembodiments, second pocket panel 239 may be eliminated entirely so thatsecond zonal insert 233 may be positioned in interstitial space 225.Pocket panel 239 generally serves the purpose of holding second zonalinsert 233 in a specific location within upper 201. In embodiments thatdo not utilize a pocket panel like second pocket panel 239, the pocketmay be formed by attaching a portion of second outer layer 220 directlyto inner knit layer 222, such as with integrated knitting, stitching,adhesive bonding, heat bonding, and/or welding.

The structure of a pocket, in particular, first zonal pocket 230, isshown in detail in FIGS. 12 and 13. As depicted, first zonal pocket 230is formed by associating first pocket panel 237 with outward-facingsurface 224. Therefore, outward-facing surface 224 forms a first wall offirst pocket interior 236 while first pocket panel 237 forms an oppositewall of first pocket interior 236. First pocket panel 237 may be coupledto outward-facing surface 224 on three edges, as denoted by the panelattachment line 244. The attachment of first pocket panel 237 is shownfurther in FIG. 13, which is a cross-sectional view of FIG. 12. Firstpanel attachment 251 and second panel attachment 245 may affix oppositeedges of first pocket panel 237 to outward-facing surface 224. Theattachment 245 may include sewing, adhesive bonding, heat bonding,welding, or any other suitable device or method.

The attachment of first pocket panel 237 to outward-facing surface 224may advantageously allow for easy access into first pocket interior 236.As shown best in FIG. 12, a pocket lip 242 may not be attached tooutward-facing surface 224, and pocket lip 242 may be a free end offirst pocket panel 237 that can be pulled away from outward-facingsurface 224 to permit access into first pocket interior 236. This mayallow a manufacturer to slide first zonal insert 231 into first pocketinterior 236. The same or a similar structure as first zonal pocket 230may apply equally to second zonal pocket 232 and third zonal pocket 234.

Zonal inserts 231, 233, and 235 may be configured (e.g., sized, shaped,and formed of a material with particular properties) to provide upper201 with specific properties proximate zonal pockets 230, 232, and 234.In some embodiments, all zonal inserts 231, 233, and 235 may provide thesame property to upper 201. Alternatively, each zonal insert may providedifferent properties, depending upon the location of the zonal insert onupper 201. For example, first zonal insert 231 may be sized, shaped, orotherwise configured to act as a heel counter, which may be rigid andstiff compared to the rest of upper 201. Second zonal insert 233 may besized, shaped, or otherwise configured to act as an arch support, sosecond zonal insert 233 may be sized, shaped, or otherwise configured tofollow the contours of an arch while being supportive and cushioning.Third zonal insert 235 may be sized, shaped, or otherwise configured toact as a toe cap, which may be rigid and stiff compared to the rest ofupper 201, but may be made of a more breathable material than that offirst zonal insert 231. In some embodiments, one or more zonalproperties may be common to more than one or even all zonal inserts,such as cushioning, while other properties vary from zonal insert tozonal insert, such as stiffness and breathability.

Each zonal insert 231, 233, and 235 may optionally be made from the samematerial, or one or more of the zonal inserts 231, 233, and 235 may bemade from different materials. Example materials may include natural orsynthetic rubber, foams, polymer sheets or plates, cushioning bladdersthat may be filled with foams, gas, and/or fluids, combinations of thesematerials, knit or other textiles, and/or other suitable materials andcombinations.

The embodiment(s) of FIGS. 9-13 show that zonal inserts are disposed inthe layers of upper 201 so that the zonal inserts are spaced apart/donot touch while portions of upper 201 do not contain any inserts. Inother embodiments, such as the embodiment shown in FIGS. 14 and 15,substantially the entirety of an upper 301 may include zonal insertsthat are shaped to provide properties to various zones of the upper 301.

The upper 301 of FIGS. 14-15 is similar to the upper 201 of FIGS. 9-13in many respects. For example, the upper 301 is depicted as including aknit element 318 that is folded to form an outer layer 320 and an innerlayer 322, shown in FIG. 15. Knit element 318 may be similar inmaterials and structure to knit element 218 (of FIG. 9). However, thezonal pockets formed in an interstitial space formed between outer layer320 and inner layer 322 and the zonal inserts positioned within thosepockets are different from the zonal pockets described above. In theillustrated embodiment of upper 301, the zonal pockets and zonal insertsabut each other and have irregular edges that fit together like thepieces of a puzzle. The coverage of upper 301 assists in providing anupright structural shape to upper 301, while the shapes of the pocketsand inserts are configured to follow the contours of the foot of awearer to provide more specific zonal support and properties to thevarious areas of upper 301 proximate the zonal pockets.

The depicted upper 301 includes a first irregular zonal pocket 330, asecond irregular zonal pocket 332, a third irregular zonal pocket 334,and a fourth irregular zonal pocket 336. First irregular zonal pocket330 and first irregular zonal insert 331 are disposed in heel region311. First irregular zonal insert 331 may generally have theconfiguration and properties of at least a portion of a heel counter.First irregular zonal pocket 330 is configured to receive firstirregular zonal insert 331 and conforms generally to the shape of firstirregular zonal insert 331.

Second irregular zonal pocket 332 and second irregular zonal insert 333may be partially disposed in heel region 311 and ankle region 302, spanthird midfoot region proximate sole structure 303, and terminate inforefoot region 309. Second irregular zonal insert 333 may haveproperties that provide flexible and cushioning support to the portionsof upper proximate second irregular zonal insert 333. Additionally oralternatively, second irregular zonal pocket 332 may be configured toreceive second irregular zonal insert 333 and may conform generally tothe shape of second irregular zonal insert 333. As shown in FIG. 15,second irregular zonal insert 333 may have a second thickness 343.Second thickness 343 may be uniform throughout second irregular zonalinsert 333, or second thickness 343 may vary through second irregularzonal insert 333. The variation in thickness may provide thinnedportions of irregular zonal insert 333 for enhanced flexibility orthickened portions for enhanced stiffness and support. Second irregularzonal insert 333 may also include a second perimeter edge 342 that isshaped to extend portions of second irregular zonal insert 333 away fromsole structure 303 to provide cushioning along the sides of upper 300while also providing gaps between the portions to enhance flexibility.Similarly, third irregular zonal pocket 334 and fourth irregular zonalpocket 336 may be configured to receive third zonal insert 335 andfourth zonal insert 337, respectively, and each of these elements mayinclude any of the features described above with respect to secondirregular zonal pocket 332 and second irregular zonal insert 333. Any ofthe zonal pockets of upper 301 may be constructed similarly to the zonalpockets of upper 201 (of FIG. 9), but the zonal pockets of upper 301 mayhave different shapes. Similarly, any of the zonal inserts of upper 301may optionally be made of similar materials as the zonal inserts ofupper 201, but this is not required.

In some embodiments, such as the embodiment shown in FIGS. 16-19, anupper may be knitted to include a visual and/or machine-detectable cueas to the properties of regions and/or may include visible ormachine-detectable bite lines to similarly indicate to a technician or amanufacturing machine the intended placement of elements such as a solestructure or a throat opening support. The cue and/or bite lines mayadditionally or alternatively be included for purposes of providing thearticle of footwear with desirable aesthetic properties and effects. Thefeatures illustrated by FIGS. 16-19 and described below may be used incombination with any of the other embodiments of this disclosure.

Knit element 418 depicted in FIGS. 16-19 may be similar in materials andstructure to knit element 218 (of FIG. 9). In some respects, knitelement 418 may be similar and has many of the same traits, structures,and performance characteristics of to upper 201 of article of footwear200.

While article 400 may include zonal pockets and/or zonal inserts such asthose described above, these zonal pockets are not shown for the sake ofclarity. Instead, article 400 may be provided with zonal features oradditional zonal features based on the type of yarn used in a zone, thetype of knit stitch or other knit structure used in a zone, and/or theknit density in a zone. For the purposes of this discussion, knitdensity may be considered to be the number of stitches per unit oflength or area.

FIG. 16 shows several different zones on knit element 418: a first zone430, a second zone 431, a third zone 433, a fourth zone 434, a fifthzone 435, a sixth zone 436, and a seventh zone 437. Each of these zonesmay have different structural, performance, and/or aesthetic properties.In addition to type of yarn used in a zone, the type of knit stitch orother knit structure used in a zone, and/or the knit density in a zone,some of the differing properties of the knit element 418 may includestretch resistance, breathability, and stiffness.

In the embodiment of FIG. 16, first zone 430 spans from heel 416 to toe414 along a lowermost portion of knit element 418. First zone 430 may beconfigured (e.g., with certain materials and/or surface characteristics)to receive a sole structure. In some embodiments, first zone 430 may bestiffer than other zones to form a stable surface for receiving a solestructure. In some embodiments, first zone 430 may be thicker than otherzones to form a more comfortable surface for a foot. In someembodiments, first zone 430 may include more thermoplastic polymer yarnsthan other zones so that a sole structure may be readily heat bondedand/or welded to first zone 430. In some embodiments, first zone 430 mayinclude a type of yarn that is more compatible with an adhesive than theother zones so that first zone 430 may be more easily adhesive bonded toa sole structure. In some embodiments, first zone 430 may be acombination of any of these properties.

Second zone 431 extends from midfoot region 410 and into forefoot region409 from a forward part of ankle region 402 along a top of knit element418. In some embodiments, second zone 431 may be more elastic than otherregions so that second zone 431 may stretch to accommodate a footinsertion and return to an original size to secure knit element 418 tothe foot. In some embodiments, second zone 431 may be configured toreceive a lacing system reinforcing structure. When included, the lacingsystem may include eyelets, which may be punched out of the second zone431 (e.g., post-knitting), or may be knitted directly into second zone431. In embodiments with knitted eyelets, the eyelets may be formed byknitting float stitches (for example a one- or two-stitch float on acircular knitting machine). Each eyelet may include an entrance and anexit, each of which may include one or more yarns selected fordurability and abrasion resistance. For example, knitted eyelets maycomprise high tenacity yarns and/or thermoplastic yarns activated bysuitable post-processing step. In some embodiments, second zone 431 maybe thicker than other zones to provide additional comfort to the top ofa foot proximate the laces. In some embodiments, second zone 431 mayinclude more thermoplastic yarns than other zones so that a reinforcingstructure may be readily heat bonded and/or welded to second zone 431.Optionally, second zone 431 may include a type of yarn that is morecompatible with an adhesive than the other zones so that second zone 431may be more easily adhesive bonded to a reinforcing structure. In someembodiments, second zone 431 may be a combination of any of theseproperties.

Third zone 433 may be positioned primarily in ankle region 402. Thirdzone 433 may be significantly more elastic and have greater recoverycapabilities than other zones, even than second zone 431, so that thirdzone 433 may stretch to accommodate a foot insertion and return to anoriginal size to secure knit element 418 to the ankle of a user.

Fourth zone 434 may be positioned adjacent third zone 433 and betweenfirst zone 430 and second zone 431. Fourth zone 434 may be positionedproximate a portion of knit element 418 designed to cover a portion of amalleolus area of a user's foot. In some embodiments, fourth zone 434may have stretch properties similar to third zone 433, but may also havecushioning properties or other protective properties to assist inprotecting the ankle of a wearer. In some embodiments, fourth zone 434may be stiffer and/or less stretchy than third zone 433 to inhibit anypotential rolling motion of a user's ankle. For example, fourth zone 434may be selectively knit with yarns having thermoplastic characteristics(e.g., that stiffen when heat activated) in order to provide anklesupport.

Fifth zone 435 may be positioned adjacent to fourth zone 434 and betweenfirst zone 430 and second zone 431. In some embodiments, fifth zone 435may be stiffer than the surrounding zones to provide stability to knitelement 418. For example, fifth zone 435 may be selectively knit withyarns having thermoplastic characteristics (e.g., that stiffen when heatactivated) in order to provide medial and lateral support.

Sixth zone 436 may be positioned adjacent to fifth zone 435 and extendsbetween first zone 430 and second zone 431. In some embodiments, sixthzone 436 may be less stiff than the surrounding zones to increase theflexibility of knit element 418 proximate the toe joints of a user.

Seventh zone 437 may be positioned in fourth forefoot region 409 and isconfigured to cover the toes of a user when the user's foot is insideknit element 418. In some embodiments, seventh zone 437 may be morebreathable than the surrounding zones. In other embodiments, seventhzone 437 may incorporate materials, such as yarns with thermoplasticpolymer materials, that aid in the formation of toe seam 132, asdescribed above.

FIG. 17 shows an embodiment of an unfolded element 518 that may befolded or otherwise manipulated into a double-layer knit element likeknit element 418. Unfolded element 518 may include the same pattern ofyarns as shown in FIG. 16, or unfolded element 518 may include asimplified pattern as shown so that a first bite line 522 is positionedon a first part of unfolded element 518 and a second bite line 520 maybe positioned between first part 543 and a second part 541 of unfoldedelement 518. The simplified pattern may include a first area 530 havingfirst zonal properties, a second area 531 having second zonalproperties, a third area 532 having third zonal properties, a fourtharea 533 having fourth zonal properties, and a fifth area 534 havingfifth zonal properties, and the like. The zonal properties may be any ofthe types of zonal properties noted above with respect to knit element418, or any other suitable type. In this simplified embodiment, secondarea 531 may have similar or substantially identical properties to fiftharea 534, and third area 532 may have similar or substantially identicalproperties to fourth area 533.

FIG. 17 shows an embodiment of unfolded element 518 where unfoldedelement 518 has a generally tubular, sock-like configuration. First part543 and second part 541 are nearly identical in shape, thoughmirror-images or oppositely-oriented. In some embodiments, first part543 and second part 541 may have a foot-like shape similar to unfoldedelement 138, discussed above.

In the illustrated embodiment, first part 543 includes an open toe 540,and second part 541 has a closed toe 542, where the edges of the tubularelement have been knitted or otherwise joined together. In someembodiments, closed toe 542 may also be left open. In such embodiments,closed toe 542 may include a seam as discussed below.

Unfolded element 518 may be folded or otherwise manipulated in much thesame way as unfolded element 138 discussed above with reference to FIGS.5-8. However, unfolded element of FIG. 17 may additionally includesecond bite line 520 for use as a guide for the folding process, whileunfolded element 138 (of FIGS. 5-8) shows no such guide line. A foldingmachine may use sensors such as laser detection systems or visualinspection systems that utilize captured images of unfolded element 518and bite line 520 to detect where the main fold should be, while atechnician may be able to use bite line 520 as a simple visual guide foraccurate folding. Quality control inspection devices and inspectors mayfind that second bite line 520 or other visual/detectable cues on secondunfolded element 518 may provide for faster and more accurateinspection.

FIGS. 18 and 19 show an embodiment of how bite line 420 may be used toguide the placement of a sole structure 403 onto an upper 401 thatincludes knit element 418. As shown in FIG. 18, sole structure mayinclude a perimeter edge 423 configured (e.g., sized and shaped) tofollow the same contours as bite line 420. While shown in theillustrated embodiment as an irregular edge, perimeter edge 423 mayinstead have a smooth edge or a different contour. Bite line 420 andperimeter edge 423 may be aligned so that perimeter edge 423 follows thecontours of bite line 420. FIG. 19 shows article 400 with sole structure403 affixed to upper 401 so that sole structure 403 covers first zone430 so that perimeter edge 423 follows first bite line 420. In otherembodiments, perimeter edge 423 may obscure part or all of first biteline 420 when positioned onto upper 401. Sole structure 403 may beaffixed to upper 401 using techniques including but not limited tosewing, adhesive bonding, heat bonding, and/or welding.

FIGS. 20A-B illustrate a knitted component 601 including an outer knitlayer 620 pulled over an inner knit layer (not shown), and furtherincorporating a sole structure 603, where the outer knit layer 620incorporates a retention system 640 for exerting a tension force on awearer's foot. The retention system 640 may be incorporated intoretention zones 642 which may be preferably located on the medial and/orlateral portions of the outer knit layer 620 and extend longitudinallyalong the knitted component 601. The retention system 640 may includeone or more first yarns 650 (such as 650 a, 650 c, 650 e, and 650 g)configured to provide medial-to-lateral support (e.g., medial-to-laterallock-out) when a wearer places a foot into the knitted component 601.The retention system 640 may additionally and optionally include one ormore second yarns 660 (such as depicted second yarns 660 a, 650 c, 650e, and 650 g) for biasing the retention system 640 to a first state whena wearer's foot is not positioned within the knitted component 601.Additionally, the retention system 640 may optionally include one ormore third yarns 670 (such as the depicted third yarns 670 a, 670 c)that shield at least one first yarn 650 from abrasion, snagging, andother causes of damage while advantageously preserving ventilation andvisibility of the first yarns.

Still with reference to FIGS. 20A-B, the first yarns 650 a-g may beknitted to form intermeshed loops of outer knit layer 620 or may beinlaid within intermeshed loops of outer knit layer 620, and maygenerally have an orientation substantially in the medial and lateraldirections, in the heel and forefoot directions, or in otherorientations. It is also possible for the first yarns 650 a-g to includeat least one first yarn 650 that is inlaid and different first yarn(s)650 that are looped. Optionally, when the retention system 640 includesfirst yarns 650 with knitted loops, the first yarns 650 may includefloating portions that float (i.e., extend without a loop) past a seriesof wales. The floating portions may be formed when the floating portionsof the first yarns 650 skip (i.e., extend past without engaging) aseries of consecutive needles on a needle bed during when knitting acourse during a knitting process. The needle bed may be a needle bed ofa circular knitting machine. The course-wise length along each firstyarn 650 between the loops immediately adjacent to the ends of thefloating portion may be referred to as the float length. When firstyarns 650 are taut, the float length may form a relatively straightdimension that may be parallel to and define a course-wise dimension ofthe retention zones 642 a-b (i.e., the vertical dimension from theperspective of FIG. 20A). When the first yarns 650 are not taut, thefloat length may not form a relatively straight dimension, and may notdefine the course-wise dimension of the retention zones 642 a-b. Thenumber of consecutive floated courses of the first yarn 650 maygenerally define a wale-wise dimension of the retention zones 642 a-b(i.e., the horizontal dimension from the perspective of FIG. 20A). Thisknit structure results in each knitted first yarn 650 being loose fromthe rest of the knitted component within the retention zones 642 a-b.Because the first yarns 650 have a nominal stitch length within thefloat length, and because the first yarns 650 may be constructed from amaterial with low stretch, the first yarns 650 may have very low stretchalong the course-wise direction (depicted as vertical) within theretention zone 642 (at least when the first yarns 650 are taut).

More than one retention zone 642 may be included. As shown in FIG. 20A,for example, two retention zones 642 a-b may be included. Retention zone642 a may be spaced or otherwise separated from the retention zone 642 bby a portion 643 of the outer knit layer 620. Portion 643 of the knittedlayer may include loops formed by the first yarns 650 a-g.Advantageously, providing two (or more) retention zones 642 a-b mayincrease the amount the retention system can displace between its firstand second states with respect to the inclusion of only one retentionzone 642. Further, it is contemplated that machine limitations may limitmaximum float length of first yarns 650 a-g due to a maximum number ofneedles that may be skipped without interrupting the knitting process(e.g., 8 needles according to one test performed by an inventor). Thus,to mitigate this limitation, the portion 643 of the outer knit layer 620may include loops formed by the first yarns 650 a-g.

Suitable materials for the first yarns 650 include yarns formed withlow-stretch/low-elasticity materials with relatively high tensilestrength, e.g., cables, strands, and cords. Exemplary materials that maybe used for first yarns 650 may include strands or fibers having a lowmodulus of elasticity as well as a high tensile strength, such astensile strands of monofilament material with a diameter ofapproximately 0.5 mm-2.0 mm, or fibers such as SPECTRA™, manufactured byHoneywell of Morris Township N.J. Other suitable materials for firstyarns 650 include various filaments, fibers, and yarns, that are formedfrom rayon, nylon, polyester, polyacrylic, silk, cotton, carbon, glass,aramids (e.g., para-aramid fibers and meta-aramid fibers), ultra-highmolecular weight polyethylene, and liquid crystal polymer. In comparisonwith the second yarns 660, the thickness of the first yarns 650 may begreater.

Still with reference to FIGS. 20A-B, the second yarns 660 a-g may beknitted to form intermeshed loops of outer knit layer 620 or may beinlaid within intermeshed loops of outer knit layer 620, and may havemechanical properties (e.g., a particular elasticity and resilience) forbiasing the retention system 640 to a first state when the knittedcomponent 601 is not on a wearer's foot. Exemplary materials for thesecond yarns 660 a-g may include yarns that incorporates elastanefiber(s), such as those available from E.I. duPont de Nemours Companyunder the LYCRA trademark. Such yarns may have the configuration ofcovered LYCRA, for example yarns having a LYCRA core that is surroundedby a nylon sheath. Other fibers or filaments exhibiting elasticproperties may also be utilized.

Still with reference to FIG. 20A, the third yarns 670 (shown as 670 a-cin FIG. 20A and not shown in FIG. 20B) may be knitted to form a knitstructure of intermeshed loops of the outer knit layer 620 or inlaidwithin intermeshed loops of outer knit layer 620. The third yarns 670may include yarns with suitable durability, such as monofilament yarnsor other yarn with high resistance to abrasion and breakage. In FIG.20A, third yarns 670 a-c are represented schematically, and FIG. 20Adoes not necessarily correspond to the orientation or stitch type ofthird yarns 670 a-c. Generally, third yarns 670 may be formed from aknit stitch, tuck stitch, or other suitable stitch or other knitstructure, and may be oriented as necessary to form a lattice, covering,or other protective knit structure for the first yarns 650. In someembodiments, at least one of the first yarns 650 may reside behind atleast one of the third yarns 670 when the outer knit layer 620 is pulledover the inner knit layer 622, so that an exterior surface of at leastone of the first yarns 650 is covered by at least one of the third yarns670. In other words, in use, when a wearer's foot is placed within theknitted component 601, at least one of the first yarns 650 may residebetween the wearer's foot and at least one of the third yarns 670, i.e.,at least one of the third yarns 670 may reside over at least one of thefirst yarns 650.

Still with reference to FIG. 20A, before a wearer places a foot in theknitted component 601, the knitted component 601 may assume a relativelylimp, sock-like state. The second yarns 670 a-f may bias the knittedcomponent 601 to a first state, in which the second yarns 670 a-f mayassume a contracted state and the first yarns 650 a-f may assume a slackstate, as shown, where the float length of the first yarns 650 a-f isgreater than the corresponding course-wise dimension of the retentionsystem. By inserting a foot into the knitted component 601, as shown inFIG. 20B, a wearer stretches the second yarns 670 a-f into a secondstate, at which point the second yarns 670 a-f stretch and provide asnug on-foot feel by creating tension in the portion of the knittedcomponent 601 around the bridge of the wearer's foot. Also, by insertinga foot into the knitted component 601, a wearer causes the first yarns650 a-f to become taut, as shown in FIG. 20B. Because the first yarns650 a-f may be constructed of materials with relatively low stretch andhigh tensile strength, the first yarns 650 a-f may experience tensilestress in the second state and tend to resist further elongation. Thistends to retain the knitted component 601 on the wearer's foot withoutadditional steps (e.g., tying a lace), and also retain the wearer's footon the sole structure 603. In other words, the retention system exerts atension force (e.g., a tension force in the first yarns 650) to retainthe knitted component 601 on the wearer's foot. The tension force mayalso include tensile forces present in the second yarns. In someembodiments, conventional elements like a tongue may be provided. In theillustrated embodiments, however, the sock-like nature of the knitelements may not require a traditional tongue as the ankle region maystretch to accommodate foot insertion and retract to secure the footsnugly within the knitted component. In some embodiments, closureelements can also be included that is used to selectively secure aknitted component to the wearer's foot. A closure element can be of anysuitable type, such as a lace. In other embodiments, the closureelement(s) may also include one or more buckles, straps, or othersuitable implements for securing the knitted component to a wearer'sfoot. In the illustrated embodiments, however, the knitted component maybe configured to be pulled over a user's foot like a sock, and, thus,may not include any additional closure elements. When a closure elementis included, the closure element may operate in conjunction with theretention system 640 of FIGS. 20A-20B, but it is also contemplated thatthe retention force provided by the retention system 640 may render anadditional closure element unnecessary.

In further configurations, any of the knitted components disclosed abovemay include additional elements. For example, upper 101 (of FIG. 1, orany other upper described herein) can include a toe guard in forefootregion that is formed of a wear-resistant material. The upper canadditionally include logos, trademarks, symbols, and placards with careinstructions and material information. It will be appreciated that anyupper disclosed above can include still further elements withoutdeparting from the scope of the present disclosure.

The filaments of the nonwoven layers, knitted materials, components, orinserts in any of the embodiments discussed above may include athermoplastic polymer material. In general, a thermoplastic polymermaterial melts when heated and returns to a solid state when cooled.More particularly, the thermoplastic polymer material transitions from asolid state to a softened or liquid state when subjected to sufficientheat, and then the thermoplastic polymer material transitions from thesoftened or liquid state to the solid state when sufficiently cooled. Assuch, the thermoplastic polymer material may be melted, molded, cooled,re-melted, re-molded, and cooled again through multiple cycles.Thermoplastic polymer materials may also be bonded or fused, asdescribed in greater detail below, to other textile elements, plates,sheets, polymer foam elements, thermoplastic polymer elements, thermosetpolymer elements, or a variety of other elements formed from variousmaterials. In contrast with thermoplastic polymer materials, manythermoset polymer materials do not melt when heated, simply burninginstead. Although a wide range of thermoplastic polymer materials may beutilized for the filaments of a nonwoven or knitted material or aninsert or component, examples of some suitable thermoplastic polymermaterials include thermoplastic polyurethane, polyamide, polyester,polypropylene, and polyolefin. Although any of the thermoplastic polymermaterials mentioned above may be utilized for the above-discussedembodiments, an advantage to utilizing thermoplastic polyurethanerelates to heat bonding and colorability. In comparison with variousother thermoplastic polymer materials (e.g., polyolefin), thermoplasticpolyurethane is relatively easy to bond with other elements, asdiscussed in greater detail below, and colorants may be added tothermoplastic polyurethane through various conventional processes.

Although each of the nonwoven layers, knitted materials, components,and/or inserts may be entirely formed from a single thermoplasticpolymer material, portions of the nonwoven layers, knitted materials,components, and/or inserts may also be at least partially formed frommultiple polymer materials. As an example, an individual filament in anonwoven or knit may have a sheath-core configuration, wherein anexterior sheath of the individual filament is formed from a first typeof thermoplastic polymer material, and an interior core of theindividual filament is formed from a second type of thermoplasticpolymer material. As a similar example, an individual filament of anonwoven or a knit may have a bi-component configuration, wherein onehalf of the individual filament is formed from a first type ofthermoplastic polymer material, and an opposite half of the individualfilament is formed from a second type of thermoplastic polymer material.In some configurations, any individual filament may be formed from botha thermoplastic polymer material and a thermoset polymer material witheither of the sheath-core or bi-component arrangements.

Finally, while the above embodiments have generally referenced structureand manufacture in the form of a shoe, the present embodimentscontemplate manufacture of articles other than shoes, such asaccessories or other apparel.

While various embodiments of the invention have been described, theinvention is not to be restricted except in light of the attached claimsand their equivalents. Moreover, the advantages described herein are notnecessarily the only advantages of the invention and it is notnecessarily expected that every embodiment of the invention will achieveall of the advantages described.

We claim:
 1. A knitted component forming an overfoot portion and anunderfoot portion of an article of footwear, the knitted componentcomprising: a first layer defining a void; a second layer, wherein thesecond layer at least partially surrounds the first layer, wherein thesecond layer forms an outer surface on the overfoot portion and theunderfoot portion, and wherein a portion of the first layer iscontinuous with a portion of the second layer in an ankle region of theknitted component; an interstitial space formed between the first layerand the second layer; and a component disposed between the first layerand the second layer.
 2. The knitted component of claim 1, wherein thefirst layer and the second layer are formed on a circular knittingmachine, and wherein the second layer is inverted with respect to thefirst layer.
 3. The knitted component of claim 1, wherein a seam isformed at least in the second layer in a toe region of the knittedcomponent.
 4. The knitted component of claim 3, wherein the seam joinsthe first layer to the second layer.
 5. The knitted component of claim1, wherein a tension force of the second layer retains the component inan underfoot area of the interstitial space.
 6. The knitted component ofclaim 1, wherein the component is retained in an underfoot area of theinterstitial space, and wherein the interstitial space is substantiallyfree of adhesive.
 7. The knitted component of claim 1, wherein thecomponent is a midsole.
 8. The knitted component of claim 1, furthercomprising: a retention system formed in the second layer, the retentionsystem comprising: a plurality of first yarns and a plurality of secondyarns, wherein the first yarns and the second yarns at least partiallyform the second layer of the knitted component, wherein the second yarnsbias the retention system to a first state, and wherein the retentionsystem exerts a tension force in a second state.
 9. An upper for anarticle of footwear, comprising: a first layer; a second layer, whereinthe second layer at least partially surrounds the first layer, wherein aportion of the first layer is continuous with a portion of the secondlayer, and wherein the first layer is continuous with the second layerin at least a portion of an ankle region of the upper; and a componentdisposed between the first layer and the second layer, wherein thecomponent comprises a material having different properties than thefirst layer and the second layer.
 10. The upper of claim 9, wherein thecomponent comprises a rigidity greater than the first layer and thesecond layer.
 11. The upper of claim 9, wherein the component comprisesa shape of a bootie that is coextensive with at least a forefoot regionand a midfoot region of the upper.
 12. The upper of claim 11, whereinthe bootie is coextensive with a portion of a heel region.
 13. The upperof claim 9, wherein the component comprises greater stretch resistancethan the first layer and the second layer.
 14. The upper of claim 9,wherein the first layer and the second layer are formed by a knittedcomponent.
 15. The upper of claim 9, wherein a pocket is disposedbetween the first layer and the second layer, wherein the pocketreceives the component.
 16. The upper of claim 9, further comprising aseam that joins the first layer to the second layer in a toe region ofthe upper.
 17. A method of making an article of footwear, the methodcomprising: pulling an open toe region of an element towards a main foldline disposed between a first portion of the element and a secondportion of the element so that an interior surface of the first portionof the element is exposed during the pulling operation; pulling the opentoe region past the main fold line and onto the second portion so thatthe first portion substantially surrounds the second portion and a foldis formed in an ankle region of the article of footwear; aligning theopen toe region of the element with a closed toe region of the secondportion of the element; and forming a seam to join the open toe regionwith the closed toe region.
 18. The method of claim 17, wherein theelement is a knitted component, and wherein the method further comprisesforming the knitted component on a knitting machine.
 19. The method ofclaim 17, wherein an interstitial space is formed between the firstportion and the second portion.
 20. The method of claim 19, furthercomprising inserting a component between the first portion and thesecond portion in the interstitial space.